Already made your choice?
I have this kraftwerk cart:
http://www.rustbuster.nl/Quickshop/index.php?48,k3908-4993-kraftwerk-gereedschapskar-special
With some extra modules
Best thing about this set is the cabinet. The drawers are really good (I compared them with the cheaper hazet, gedore etc), and there are 8 in stead of the usual 7.
Still 8 isn't enough

And the wrenches and ratchets are strong and the chrome finish doesn't show a lot of wear after about 5 years of pretty hard (non professional) use.
What I like less are the handles (from screwdrivers etc), because I like the oldfashioned hard Cellulose Acetate Butyrate handles (easier to clean, less prone to damage, and for me better grip feel), but almost nobody makes them anymore in a tool set (you have to buy seperate tools and then you won't have the molded drawer liners....)
Also the printed text on the rubber handles wears out, and the laser etched text on e.g. Torx screwdrivers is pretty small thus hard to read.
Sadly there's no such thing as a perfect and complete off the shelf toolset

I'm also still doubting if I shouldn't have gotten the 11 drawer cart in stead of the 8 drawer.
11 drawers means more space for modules, but the drawers are lower (even the slim drawers), so that can be a pain to get parts out of the back of the module (like a socket) because usually tool cart drawers do not completely clear the drawer above when the drawer is completely pulled out. (maybe a professional cabinet like lista does)
choices....choices....